More than one in three adults in America are getting less sleep than they need. While insufficient sleep is often considered normal, it can have dramatic effects on a population’s health and productivity. According to research funded by the National Institutes of Health, sleep deprivation in America is a largely unaddressed and growing public health problem.

After only one night with too little sleep, a person’s cognitive abilities are dramatically diminished. After a single night of less than six hours of sleep, the risk of a car accident doubles for drivers, according to the American Automobile Association. Further, driving with less than five hours of sleep is just as dangerous as driving at or slightly above the legal alcohol limit. Many workplace accidents are also caused by sleep deprived employees. Several massive incidents such as the Challenger explosion, the near meltdown at Three Mile Island, and the Chernobyl disaster have all been tied to sleep deprivation among workers.

Sleeping habits vary considerably across country. With data from the Centers for Disease Control and Prevention, 24/7 Wall St. reviewed the share of adults in every state who sleep less than seven hours per night. Hawaii residents get the least sleep with 43.9% of adults averaging less than seven hours each night. By contrast, only 28.4% of adults in South Dakota get insufficient sleep, the lowest share of any state.

Stress is among the leading causes of not getting enough sleep. Based on a CDC survey asking Americans to report mental well-being, 11.2% of adults experience frequent mental distress — defined as poor mental health during at least 15 days out of the previous 30. In states where residents report getting the most sleep, this percentage tends to be lower. All the 10 states where residents report the best sleeping habits have a lower share of adults with continual stress than the nation as a whole.

Low levels of income and education increase the likelihood of a population not getting enough sleep. This is likely caused by residents working longer hours at lower paying jobs and the higher level of stress from financial insecurity. Nationwide, 30.1% of adults with an annual salary over $75,000 report regular insufficient sleep. However, among those earning less than $25,000 annually, 42.2% get too little sleep. In addition, while over 40% of adults without a high school diploma report insufficient sleep, approximately 28% of those with a college degree do.

Nationwide, 14.7% of the population lives in poverty. While the poverty rate is higher in only one of the 10 states where residents get the most sleep, it is higher in seven of the 10 states where residents report getting the least sleep.

Sleeping less than seven hours per night is associated with a range of adverse health effects, including increased risk of obesity, diabetes, high blood pressure, coronary heart disease, stroke, and frequent mental distress.

Insufficient sleep, through the associated adverse health outcomes, can raise the likelihood of premature death across an entire population. Only three of the 10 states getting the least sleep have a life expectancy above the nation’s average, while eight of the 10 states sleeping the most have a longer life expectancy than the nationwide average. Those who sleep five hours or less per night have a 15% higher risk of death from all causes than those who sleep seven hours each night — according to recent research reviewed by Harvard Medical School.

To determine the states where residents report getting the most and least sleep, 24/7 Wall St. reviewed the share of adults in every state who get less than seven hours of sleep. These figures were obtained from the Centers for Disease Control and Prevention’s 2014 Behavioral Risk Factor Surveillance System (BRFSS). The share of adults in each state reporting frequent mental distress was compiled by County Health Rankings & Roadmaps, a Robert Wood Johnson Foundation and University of Wisconsin Population Health Institute joint program using 2014 CDC data. The share of adults with high blood pressure was compiled by the United Health Foundation using 2015 CDC data from the BRFSS. Poverty Rates are from the U.S. Census Bureau’s 2015 American Community Survey.